Lever-operated variable resistor

ABSTRACT

A lever-operated variable resistor comprising a case, a base plate provided at the open end of the case, a contact carrier interposed between the case and the base plate, a contactor fixed on the contact carrier, a resistance element provided on the case or the base plate and a lever provided on the side periphery of the contact carrier; in which a couple of supporting portions formed integrally with the sides of the contact carrier are fitted respectively in a couple of supporting holes formed opposite to each other in the base plate, the contactor is in contact with the resistance element, and the lever is projected through a slot formed on the side wall of the case.

United States Patent 1151 3,699,493 Oka et al. [45] Oct. 17, 1972 [54] LEVER-OPERATED VARIABL 2,120,651 6/1938 Schellinger ..338/132 RESISTOR 3,544,946 12/1970 Murokami ..338/174 [72] Inventors: Shunzo Oka, Hirakata; Akitoshi FOREIGN PATENTS OR APPLICATIONS bmh Japan 606,236 7/1956 Canada ..338/128 [73] Assignee: Matsushita Electric Industrial Co.,

-a Osaka, Japan Primary Examiner-Lewis l-l. Myers 22 Fi] d: s t. 2 1971 Assistant Examiner-Gerald P. T0111) 1 6 ep Attorney-Stevens, Davis, Miller & Mosher [21] Appl. No.: 184,369

[57] ABSTRACT Foreign Application Data A lever-operated variable resistor comprising a case, a

Sept. 30, 1970 Ja an ..45/97559 heee Plate Previded at the Open end cf the case, a Sept 30 1970 Japan "45/9756O tact carrier interposed between the case and the base 0m. 13, 1970 Ja an ..45/102083 Plate, e cchtectct fitted ch the contact carrier e Oct. 13, 1970 Ja an ..45/102084 eietahce element Provided ch the case Of the hese Oct. 13, 1970 Japan ..45/102085 Plate and a lever provided on the side periphery of the Oct. 13, 1970 Japan ..45/102086 cchtect carrier; in which e couple cf Supporting P Oct. 13, 1970 Japan ..45/102037 tichs formed integrally with the Sides of the eenteet carrier are fitted respectively in a couple of supporting 52 U.S. c1 ..338/132, 338/174 holes formed opposite to eeeh Other in the base Plate, 51 lm. Cl. ..H0lc 9/02 the echtectcr is in contact with the resistance element, 58 Field of Search ..338/128, 130, 132, 162, 174 end the lever is Projected through e Slot formed on the side wall of the case. [56] References Cited UNITED STATES PATENTS 9 Claims, 15 Drawing Figures 3,035,241 5/1962 Barden ..333/174 PATENTEDUCT 17 I972 SHEET 1 [1F 4 PATENTED BET l 7 I972 SHEET 2 BF 4 PATENTEDHBI 11 1912 9.999 .493

SHEET 3 OF 4 FIG. 8

PATENTEUHBI 17 I972 I 3599 93 sum u or 4 jmj Fl 6. l 3

The present invention relates to a lever-operated variable resistor.

The linear sliding variable resistors now widely used have the advantage that the position of the knob is known at a glance, but their disadvantage lies in that fine adjustment is difficult since its sliding portion constitutes a free end.

The present invention is aimed at overcoming the above-mentioned difficulty of the conventional variable resistors and one of its objects is to provide a levervoperated variable resistor comprising a case, a base plate provided at the open end of the case, a contact carrier of insulating material interposed between the case and the base plate, a contactor fixed on the contact carrier, a resistance element provided on the case or the base plate and a lever provided on the side periphery of the contact carrier; in which a couple of supporting portions formed integrally with the sides of the contact carrier are fitted respectively in a couple of supporting holes formed opposite to each other in the base plate, the contactor is maintained in contact with the resistance element, and the lever is projected through a slot formed on the side wall of the case.

According to the device of the present invention, the value of resistance is known by just taking a glance at the position of the lever (knob). Also, since a contactor-mounted portion rotates around a fulcrum (supporting point), fine adjustment can be effected very easily. Further, operation within a small range results in a wide variation in resistance value, making the device quite suitable for the balancing of a stereo phenograph and adjustment of the volume and tone of a sound produced from an electronic musical instrument. In addition, since metal fittings mounted on a chassis act as a shield plate, a smaller number of parts suffices, simplifying the assembling processes and offering a low-cost product. Circular movement of the lever makes possible a three-dimensional panel, which enables production of an article of the most novel design.

The above and other objects, features and advantages will be made apparent by the detailed description taken in conjunction with the accompanying drawings, in which:

FIG. 1 is a front view of a lever-operated variable resistor embodying the present invention;

FIG. 2 is a bottom view showing the embodiment of FIG. 1;

FIG. 3 is a sectional view taken in the line III-III in FIG. 1;

FIG. 4 is a diagram showing a front view of another embodiment of the present invention;

FIG. 5 is a bottom view of the embodiment as shown in FIG. 4;

FIG. 6 is a sectional view taken in the line VI-VI of FIG. 4;

FIG. 7 is a plan showing still another embodiment of the present invention which comprises a lever-operated variable resistor with a click stop;

FIG. 8 is a sectional view showing the embodiment of FIG. 7; Y

FIG. 9 is a bottom view showing the embodiment of FIG. 7;

FIG. 10 is a perspective view of a case constituting the resistor according to the embodiment of FIG. 7;

2 FIG. 11 is a diagram showing a perspective view of a click-stop spring used in the embodiment of FIG. 7;

FIG. 12 is a plan showing a lever-operated multithrow variable resistor according to still another embodiment of the present invention;

FIG. 13 is a sectional view showing the embodiment of FIG. 12;

FIG. 14 is a diagram showing a plan of the leveroperated multi-throw variable resistor according to still another embodiment of the invention; and

FIG. 15 is a sectional view of the embodiment of FIG. 14.

First, explanation will be made of the first embodiment shown in FIGS. 1 to 3. Referring to FIG. 1, the reference numeral 1 shows a cap-like case formed by drawing a metal plate, which is provided with a base plate of insulating material attached to its open end with a plurality of bent legs 3. Numeral 4 shows a metal fitting which is also attached to the bottom of the base plate by means of the bent legs 3 and which has arm portions 5 with engaging holes 6 on both sides for engagement with electrical equipment (not shown). Numeral 7 shows a contact carrier of insulating material interposed between the case 1 and the base plate 2. At the centersof the upper and lower sides of the contact carrier, there are supporting portions 8 fitted in the supporting holes 9 and 10 formed respectively opposed to the bottom of the case 1 and the base plate 2, so that the contact carrier 7 rotates around the supporting portions 8. Numeral 11 shows a contactor fixed on the under side of the contact carrier 7, in which the spring arm 12 are in contact with the arcuate resistance element 13 while a portion of the contactor is maintained in contact with a collector 14. Numeral 15 shows an outer terminal extended from the ends of the resistance element 13, and numeral 16 a middle terminal connected with the collector 14. Numeral 17 shows a lever provided at a portion on the side periphery of the contact carrier 7. This lever 17 is projected through a slot 18 formed on the side wall of the case 1. The contact carrier 7 is rotated by operating the lever 17 which is usually covered with a knob (not shown).

Rotation of the contact carrier 7 causes the contactor 11 to slide along the resistance element 13 provided on the base plate 2. As a result, it is possible to obtain a desired resistance value from between one of the outer terminals 15 and the middle terminal 16.

The above-described embodiment uses the resistance element 13 disposed on the base plate 2. The cap-like case 1 may be made of moulded plastic with its opening provided with the metal base plate 2, while mounting the resistance element 13 on the case 1.

Referring to the embodiment of FIGS. 4 to 6 which are almost identical with the first embodiment, like parts are marked with the same reference numerals and the explanation here will be limited to the difference from the first embodiment.

In the second embodiment, numeral 4' shows a metal fitting for a panel constituting a shield plate, which is attached on to the bottom of the base plate 2 by means of bent legs 3. The metal fitting 4 has a ear 5' with holes 6 for engagement with a panel of the chassis of the electrical equipment.

The lever 17 provided on the side of the contact carrier 7 is projected through the slot 18 formed on the side wall of the case land the slot 19 formed in the ear 5-of the metal fitting 4. The lever 17 which is usually covered with a knob (not shown) is operated to rotate the contact carrier 7 s Explanation will be made now of the third embodiment with reference to FIGS. 7 to 11. The reference numeral 101 shows'a cap-like case made by'forming a metal plate, which has at its open end a base plate 102 of insulating material attached to it by means of bent legs 103. On thebottom of the case 101, there are a plurality of recesses 104 and 105 on both of the right and left sides which-are-not exactly symmetrical but slightly asymmetrical. Numeral 106 shows a metal fitting which is attached to the bottom of the base plate each other in the bottom of the case 101 and the base plate 102, so that the contact carrier 108 rotates around the supporting portion 109. Numeral 1 12 shows a contactor attached to the bottom of the contact carrisist'ance element 114 on the-base plate 102, while a portion of the contactor 112 is maintained in contact with the collector 115. Numeral 116 shows outer terminals connected with the ends of the resistance element 114, and numeral 117 a middle terminal led from the collector '115. Numeral 118 shows a click stop spring with its engaging hole 120 engaged with the engaging protrusion 119on the contact carrier108. This spring 118 is provided with the end spring arms 121 and 122 at symmetrical positions which are fitted in the recesses 104 and 105 on the case 101 to cause click action. It is so constructed that while one of the spring arm is engaged with the corresponding recess, the other spring arm is prevented from fitting in its recess. Numeral 123 shows a lever provided at a portion of the periphery of the contact carrier 108, which is projected through the slot 124 formed on the side wall of the case 101 and through the slot 125 formed in the engaging car 107 of the metal fitting 106. The lever 123 which is usually covered with a knob (not shown) is operated to rotate the contact carrier 108. Numeral 126 shows a stop protrusion cut up from the case 101, which is in contact with the contact carrier 108 to control the whole rotational angle of the contact carrier 108 and hence the lever 123. Rotation of the contact carrier 108 causes the contact1l2 to slide on the resistance element 114 mounted on the base plate 102, making it possible, to obtain a' desired resistance value from between one of the outer terminals 116 and the middle terminal 117. With the rotation of the contact carrier 108, the end spring arms 121 and 122 of the click stop spring 118 are alternately fitted in the recesses 104 and 105 for clicking operations. In other words, when the end spring'arm 121 is so operated as to be fitted in the recess 104, the spring arm 122 is prevented from engaging with the recess 105. On the other hand, while the end spring arm 122 is fitted in one of the recesses 105 for clicking action, the end spring arm 121 is not engaged with any of the recesses 104. In this way, the

. end spring arms 121 and 122 are alternately fitted in .er 108 with the ends 113 in contact with the arcuate re- I the recesses 104 and 105. for clicking operation.

Instead of employing two end spring arms on the click stop spring as in the above-mentioned embodi ment, more than two spring arms may be provided so far as recesses in an equal number are formedion the case 101. Also, the recesses which are formed in the case 101 in the preceding embodiment may be formed on a guide plate which is inserted in the bottom of the case 101. Further, the recesses may be replaced by holes for engagement with the end spring arms 121 and 122 of the click stop spring 1 18 to perform clicking action. x

Explanation will be made now of the fourth embodiment with reference to FIGS. 12 and 13. The reference numeral 201 shows a caplike case produced'by drawing a metal plate, which has a plurality of engaging legs (not shown) at its open end whereby the base'plate 2.02 is attached to it. Numeral 204 shows a-metal fitting which is also attached to-the lower side of the base plate by means of the bent'legs of the case 201. The metal fitting 204 has ears 205 to hold a panel (not shown) of electrical equipment on the periphery thereof The metal fitting 204 is also provided with a plurality of cut-up connecting'arms 206 on the lower side thereof. Numeral 207 shows a contact carrier of insulating material interposed between the case 201 and thebase plate 202. The supporting portions 208 integrated with the central portions of the upper and 9 lower sides of the contact carrier 207 arefitted in the with the recess 211. Numeral 212 shows a'contactor fixed on the under side of the contact carrier 207, and its end spring arm 213 is in contact with the arcuate resistance element 214 on the base plate 202, while the collector 215 is' maintained in contact with a portion of the contactor 212. Numeral 216 shows outer terminals led from the ends of the resistance element 214 and numeral 217 a middle terminal taken out of the collector 215. Numeral 218 shows a lever which is mounted on the side of the contact carrier 207 and projected through the slot 219 formed in the side wall of the case 201 and the slot 220 formed in the ear 205 of the metal fitting 204. The lever 218 which usually has a knob (not shown) at its top is operated to rotate the contact carrier 207. Numeral 221 shows a stop protrusion formed on the case 201, which, in contact with a portion of the contact carrier 207, controls the whole rotational angle of the lever 218.

Numeral 222 shows a cap-like case which is made from a metal plate by drawing and which is attached to the metal fitting 204 by being fixedly fitted in the mounting hole 223 on the bottom of the connecting arm 206. At the open end of the case 222, there is a base plate 224 of insulating material attached to the open end by means of a plurality of bent legs (not shown). Numeral 225 shows a joint shaft with its end protrusion 226 fitted in the recess 211 formed in the supporting portion on the lower side of the contact carrier 207. The other end 227 of the joint shaft 225 is fitted in the supporting hole formed in the base plate 224. Numeral 229 shows a contact carrier caulked on the middle stage of the joint shaft 225, which has a contactor 231 fixed on the lower side thereof, while the end spring arm 232 of the contactor 231 is in contact with the resistance element 233 on the base plate 224. Numeral 234 shows a collector which is maintained in contact with a portion of the contactor and numeral 235 shows a middle terminal taken from the collector 234. Although not shown in the drawing, outer terminals 236 are led from the ends of the resistance element 233.

The lever 218 is operated to rotate the contact carrier 207 and the joint shaft 225 at the same time, which in turn causes the contactors 212 and 231 to slide on the resistance elements 214 and 233 mounted on the base plates 202 and 224. As a result, it is possible to obtain a desired resistance from between one of the outer terminals 216 and the middle terminal 217 and between one of the outer terminals 236 and the middle terminal 235.

The effect of the invention remains the same if the recess 211 on the supporting portion 208 on the under side of the contact carrier 207 is replaced by a protrusion, and the end protrusion on the joint shaft by a recess. Also, it is obvious that the connecting arm 206 of the metal fitting 204 used in the above-mentioned embodiment for connecting the first-stage variable resistor and the second-stage variable resistor may be replaced by other appropriate means.

' The fifth embodiment of the invention will be now explained with reference to FIGS. 14 and 15. In the drawings, numeral 301 shows a cap-like case made by drawing a metal plate, to the open end of which the base plate 302 of insulating material is attached by means of a plurality of bent legs (not shown). Numeral 303 shows a metal fitting which is also attached on the under side of the base plate 302 by means of the bent legs of the case 301. The metal fitting 303 is provided with ears 304 forengagement with a panel of the chassis of an electrical equipment and a plurality of connecting arms 305 cut up from the lower side thereof.

Numeral 306 shows an operating shaft with its end 307 fitted in the supporting hole 308 formed on the bottom of the case 301 and with the other side projected downward through the holes 309 and 309' formed in the base plate 302 and the metal fitting 303. Numeral 310 shows a contact carrier fixedly caulked on the receiving portion 311 in the first step of the operating shaft 306. The contact carrier 310 is prevented from being loosened vertically by the bottom of the case 301 and the base plate 302 which are respectively in contact with the spacer 312 on the periphery of the operating shaft 306 and the protrusion 313 integrated with the contact carrier 310. Numeral 314 shows a contactor fixed on the under side of the contact carrier, which has the end spring arm 315 in contact with the arcuate resistance element 316 provided on the base plate 302, while a portion of the contactor is maintained in contact with the collector 317. Numeral 318 shows outer terminals derived from the ends of the resistance element 316 and the numeral 319 a middle terminal led from the collector 317. Numeral 320 shows a lever mounted at a certain portion of the periphery of the contact carrier 310, which is projected through the slot 321 formed in the side wall of the case 301 and the slot 322 formed in the ear 304 of the metal fitting 303. Numeral 323 shows a stop protrusion formed on the case 301 for controlling the whole rotational angle of the lever 320 when a part of the contact carrier 310 is brought into contact with the stop protrusion.

Numeral 324 shows a cap-like case made by drawing a metal plate, which is mounted on the metal fitting 303 through its holes 325 made in its bottom. The connecting arm 305 of the metal fitting is fixedly caulked in the hole 325. At the open end of the case 324, there is a base plate 326 of insulating material fixed by means of a plurality of bent legs (not shown). The rear end of the operating shaft 306 is engaged with the supporting hole 328 formed on the base plate 326, while the middle portion thereof is inserted through the hole 329 formed on the case. Numeral 330 shows a contact carrier fixedly caulked at the receiving portion of the second step of the operating shaft 306. On the under side of the contact carrier is fixed the contactor 332, the end spring arm 333 of which is in contact with the resistance element 334 on the base plate 326. Numeral 335 shows a contact which is maintained in contact with part of the contactor 332 and numeral 336 a mid dle terminal taken from the collector 335. Although not shown in the drawing, an outer terminal 337 is led from the ends of the resistance element 334.

The lever 320 which is usually topped with a knob (not shown) is operated to cause the operating shaft 306 to rotate around the ends 307 and 327 fitted in the supporting holes 308 and 328. Then, the end spring arms 315 and 333 of the contactors 314 and 332 fixed on the contact carrier 310 and 330 slide on the resistance elements 316 and 334 mounted on the base plates 302 and 326. As a result, a desired resistance can be obtained from between one of the outer terminals 318 and the middle terminal 319 and one of the outer terminals 337 and the middle terminal 336.

Instead of the connecting arm 305 of the metal fitting 303 used in the above-described embodiment as a connecting means between the first-stage and second-stage variable resistors, it is obvious that various other possibilities may be turned to.

We claim:

1. A lever-operated variable resistor comprising a cap-like case, a base plate mounted on the open end of said case, a contact carrier made of insulating material and interposed between said case and said base plate, a contactor fixed on said contact carrier, a resistance element mounted on either said case or said base plate and having an outer terminal extended from the end thereof, a lever mounted on the side periphery of said contact carrier, and a collector being electrically in contact with a portion of said contactor and having a middle terminal connected thereto, said case and said base plate being provided with a couple of supporting holes opposed to each other, said supporting holes receiving supporting portions integrally formed on both sides of said contact carrier of insulating material, said contactor being in contact with said resistance element, said lever projecting through a slot formed in the side wall of said case.

2. A lever-operated variable resistor according to claim 1, further comprising a metal fitting for attaching a panel serving as a shield plate on the under side of 7 saidv baseplate, said metal fitting having a pair of arm portions'each' of which having an engaging hole.

3; A lever-operated variable resistor according to claim 1, further comprising a metal fitting for attaching a panel serving as a shield plate on the under side of said base plate, said metal fittinghaving a ear-shaped tact with a portion of said contactor and having a middle terminal connected thereto, a click stop spring with .end protrusions attached to the upper side of said contact carrier, a guide plate inserted into said case or mounted on the. bottom of said case, a lever mounted on the side periphery of said contact carrier, said supporting portions being fitted in the supporting holes provided in the top'wall of said case and said base plate, said supporting holes being opposed to each other, said contactor being: in contact with said resistance element, said guide plate being provided with a recess or a hole in which said end protrusion of said click stop spring is to be fitted in, said lever being projected through a slot formed on the side wall of said case.

5. A lever-operated variable resistor according to claim 4, in which said recess or hole is so arranged that when one of said end protrusions of said click stop spring is fitted in said recess or hole, the other end protrusion is prevented from being fitted in said recess or hole.

' 6. A lever-operated multi-throw variable resistor comprising a first-stage variable resistor, a secondstage variable resistor, a joint shaft connecting mechanically said first-stage and said second-stage variable resistors, and a lever for effecting variable resistance, each of said first-stage and said second-stage variable resistors including a cap-like case, a base plate mounted at the open end of said case, a contact carrier of insulating material interposed between said case and said base plate, a contactor fixed on said contact carrier, a resistance element mounted on said base plate and having an outer terminal extended from the ends thereof, and a collector being electrically in contact with a portion of said contactor and having a middle I on both sides thereof formed integrally therewith, said supporting portions being fitted in a couple of supporting holes formed in the upper wall of said cap-like case and said base plate of said first-stage variable resistor opposite to each other, said contact carrier of said second-stage variable resistor being mounted on the middle stage of said jointshaft, said joint shaft having a protrusion or recess at the upper end thereof fitted in a recess or protrusion formed in the'und'er side' of said supporting portions and having the rear end fitted in a supporting hole formed in' said base plate of said second-stage variable resistor, said lever being mounted on the side periphery of said contact carrier of said first-stage resistor and being projected through a slot formed in the side wall of said case of said firststage resistor. g I

7. A lever-operated multi-throw variable resistor according to claim 6, in which the bottom surface of said cap-like case constituting said second-stage variable resistor is fixedly caulked on a connecting arm of a metal fitting attached to the lower side of said base plate constituting said first-stage variable resistor. I

8. A lever-operated multi-throw variable resistor comprising a first cap-like case constituting a first-stage variable resistor, a first base plate provided at the open end of said case, an operating shaft with its end fitted in a supporting hole forrned'in the bottom of said case, a second cap-like case constituting a second-stage resistor, a second base plate provided at the open end of said second cap-like case, a first contact carrier interposed between said first case and said first base plate, a second contact carrier interposed between said second case and said second base plate, contactors fixed on each of said contact carrier and a lever provided on the side periphery of said first contact carrier, collectors respectively being electrically in contact with a portion of said contactors and each having a middle terminal connected thereto, said operating shaft having one of its ends fitted in a supporting hole formed in the bottom of said first case, the rear end of said operating shaft being fitted in a supporting hole formed in said second base plate, said contact carrier being attached to said operating shaft, said contactors being in contact with resistance elements provided on said first and second 

1. A lever-operated variable resistor comprising a cap-like case, a base plate mounted on the open end of said case, a contact carrier made of insulating material and interposed between said case and said base plate, a contactor fixed on said contact carrier, a resistance element mounted on either said case or said base plate and having an outer terminal extended from the end thereof, a lever mounted on the side periphery of said contact carrier, and a collector being electrically in contact with a portion of said contactor and having a middle terminal connected thereto, said case and said base plate being provided with a couple of supporting holes opposed to each other, said supporting holes receiving supporting portions integrally formed on both sides of said contact carrier of insulating material, said contactor being in contact with said resistance element, said lever projecting through a slot formed in the side wall of said case.
 2. A lever-operated variable resistor according to claim 1, further comprising a metal fitting for attaching a panel serving as a shield plate on the under side of said base plate, said metal fitting having a pair of arm portions each of which having an engaging hole.
 3. A lever-operated variable resistor according to claim 1, further comprising a metal fitting for attaching a panel serving as a shield plate on the under side of said base plate, said metal fitting having a ear-shaped portion provided with a slot and an engaging hole, said lever being projected through said slot.
 4. A lever-operated variable resistor comprising a cap-like case, a base plate mounted on the open end of said case, a contact carrier of insulating material interposed between said case and said base plate, supporting portions formed integrally with both sides of said contact carrier, a contactor fixed on the under side of said contact carrier, a resistance element mounted on said base plate and having an outer terminal extended from the ends thereof, a collector being electrically in contact with a portion of said contactor and having a middle terminal connected thereto, a click stop spring with end protrusions attached to the upper side of said contact carrier, a guide plate inserted into said case or mounted on the bottom of said case, a lever mounted on the side periphery of said contact carrier, said supporting portions being fitted in the supporting holes provided in the top wall of said case and said base plate, said supporting holes being opposed to each other, said contactor being in contact with said resistance element, said guide plate being provided with a recess or a hole in which said end protrusion of said click stop spring is to be fitted in, said lever being projected through a slot formed on the side wall of said case.
 5. A lever-operated variable resistor according to claim 4, in which said recess or hole is so arranged that when one of said end protrusions of said click stop spring is fitted in said recess or hole, the other end protrusion is prevented from being fitted in said recess or hole.
 6. A lever-operated multi-throw variable resistor comprising a first-stage variable resistor, a second-stage variable resistor, a joint shaft connecting mechanically said first-stage and said second-stage variable resistors, and a lever for effecting variable resistance, each of said first-stage and said second-stage variable resistors including a cap-like case, a base plate mounted at the open end of said case, a contact carrier of insulating material interposed between said case and said base plate, a contactor fixed on said contact carrier, a resistance element mounted on said Base plate and having an outer terminal extended from the ends thereof, and a collector being electrically in contact with a portion of said contactor and having a middle terminal connected thereto, said contact carrier of said first-stage variable resistor having supporting portions on both sides thereof formed integrally therewith, said supporting portions being fitted in a couple of supporting holes formed in the upper wall of said cap-like case and said base plate of said first-stage variable resistor opposite to each other, said contact carrier of said second-stage variable resistor being mounted on the middle stage of said joint shaft, said joint shaft having a protrusion or recess at the upper end thereof fitted in a recess or protrusion formed in the under side of said supporting portions and having the rear end fitted in a supporting hole formed in said base plate of said second-stage variable resistor, said lever being mounted on the side periphery of said contact carrier of said first-stage resistor and being projected through a slot formed in the side wall of said case of said first-stage resistor.
 7. A lever-operated multi-throw variable resistor according to claim 6, in which the bottom surface of said cap-like case constituting said second-stage variable resistor is fixedly caulked on a connecting arm of a metal fitting attached to the lower side of said base plate constituting said first-stage variable resistor.
 8. A lever-operated multi-throw variable resistor comprising a first cap-like case constituting a first-stage variable resistor, a first base plate provided at the open end of said case, an operating shaft with its end fitted in a supporting hole formed in the bottom of said case, a second cap-like case constituting a second-stage resistor, a second base plate provided at the open end of said second cap-like case, a first contact carrier interposed between said first case and said first base plate, a second contact carrier interposed between said second case and said second base plate, contactors fixed on each of said contact carrier and a lever provided on the side periphery of said first contact carrier, collectors respectively being electrically in contact with a portion of said contactors and each having a middle terminal connected thereto, said operating shaft having one of its ends fitted in a supporting hole formed in the bottom of said first case, the rear end of said operating shaft being fitted in a supporting hole formed in said second base plate, said contact carrier being attached to said operating shaft, said contactors being in contact with resistance elements provided on said first and second base plates respectively, said resistance elements each having an outer terminal extended from the end thereof, said lever being projected through a slot formed on the side wall of said first case.
 9. A lever-operated multi-throw variable resistor according to claim 8, in which the bottom of said second cap-like case constituting said second-stage variable resistor is fixedly caulked on a connecting arm of a metal fitting provided on the lower side of said first base plate constituting said first-stage variable resistor. 